Upland bully

Gobiomorphus breviceps (Stokell, 1940)

The upland bully is one of the non-diadromous members of the Eleotridae family. That means they live their whole lives in fresh water. Adult male upland bullies are relatively easy to identify - they have orange spots on their cheeks and head, and the outer edge of the dorsal fin is also orange. Immature fish and females are less easy to identify, particularly where their distribution overlaps with Crans bully in the lower North Island. Experts have to rely on pectoral fin ray counts under a microscope to ensure that upland bullies can be distinguishd from Crans bullies.

Upland bullies are common along the east coast of the South Island. On the west coast, they occur in the Hokitika, Grey, and Buller River systems, but are absent from rivers north and south of there. It was recorded for the first time on Stewart Island in 1998. In the North Island, upland bullies are found from the Ruamahanga River catchment up to the Wanganui and Patea systems. They do not occur in the northern half of the North Island.

Because upland bullies do not have to go to sea as part of their life cycle, they occur well inland in many river systems. But they are also found close to the coast. They will tolerate a variety of habitats, from stony-bedded rivers to weedy streams, and have even established populations in a few South Island lakes, e.g. Lake Coleridge.

Like all the bully species, the males establish and defend territories during the breeding season. This accounts for their more dramatic colouration compared to the females. The eggs are laid in a primitive nest, which is usually the underside of a large rock. However, instream debris such as wood can also be used. After the eggs are laid, the male guards the nest from intruders and fans the eggs to keep them oxygenated. There is no parental care after hatching.